Process for waterproofing fibrous materials



(6) Drying the fibrous material United States PatenrO PROCESS FOR WATERPROOFING FIBROUS MATERIALS No Drawing. Filed June 11, 19 57, Ser. No. 664,897 Claims priority, application Germany June 15, 1956 Claims. (Cl. 117-1355) This invention relates to a process for waterproofing fibrous materials, and more particularly to a method of imparting Water-repellent properties to fibrous materials with the aid of condensation products formed from metal alcoholates and acid high-molecular organic derivatives of phosphoric acid.

We have found that high-grade water-repellent impregnations are obtained in fibrous materials if such materials are impregnated with solutions of condensation products formed by metal alcoholates and acid highmolecular organic derivatives of phosphoric acid, especially acid alkyl phosphoric acid esters of high-molecuiar organichydroxyl compounds, in organic solvents; the solutions may, if desired, contain small amounts of complex-stabilizing products. invention may be advantageously applied to all types of The process according to the fibrous materials, such as textile fibers, textile fabrics, furs, feathers, paper, cardboard, cellulose, wood, and the like. Depending upon the amounts and conditions, the process described herein imparts water-repellent, water-resistant or Water-impermeable properties to the fibrous materials.

In tabular form our process for impregnating fibrous materials is as follows:

.(l) Solution of the aluminum alcoholate in an organic solvent.

(2) Solution of the diacid phosphoric acid monoester of high molecular weight organic hydroxyl compound in the solution obtained from step 1.

(3) Heating of the solution from step 2 to 30 to 50 C.

for a short period of time (optional) (4) Solution of an organic complex stabilizing compound in the solution obtained from either step 2 or step 3 (optional) (5 impregnating, by immersion, brushing or spraying, the dry fibrous material'with the solution obtained from steps 2, 3, or 4.

the fibrous material.

,(7 Subsequent treatments if necessary.

.Forthe production of the waterproofingagent used in accordance with the present invention, primarily aluminum alcoholates, such as aluminum isop-ropylate, aluminum. butylate, aluminum octylate, aluminum -dodecylate, or alcoh'olates of other, preferably low-molecular, organic hydroxyl compounds, the alkyl radicals of which mayalso comprise substituents, such as halogen, may be used as starting materials.

or alternatively steaming,

2,911,249 Patented Mar. 28, 1961 vice . .2 which contain basic groups, as well as mixtures of various alcoholates. 1

Phosphoric acid esters of organic hydroxyl compounds suitable for the production of the condensation products used as waterproofing agents in accordance with the presentinvention are primarily the corresponding monoalkyl esters with-alkyl radicals having at least 6 carbon atoms in the alkyl chain, such as phosphoric acid monooctyl ester, phosphoric acid monododecyl ester, phosphoric acid monooleyl ester, as well as phosphoric acid monoalkylphenol esters wherein the alkyl radicals have from 3 to 18 carbon atoms, phosphoric acid mononaphthenyl ester, phosphoric acid monoabietyl ester, and the like. vFurthermore, the corresponding di-esters, inadmixture with mono esters, may be used, as well as. those'esters the alcohol radicals of which carry substituentsor' are'interrupted by oxygen, sulfur or nitrogen atoms or by groups containing oxygen, sulfur and/or nitrogen. In place of the acid phosphoric acid esters, also other high;- molecular organic derivatives of phosphoric acids maybe used, such as the corresponding acid phosphoric acid alkyl amides, alkyl phosphonic acids, alkyl phosphinic acids, and the like. 1

From these two components condensation products are formed in the presence of inert organic solvents, such as isopropanol, trichloroethylene or toluene, as well as other low-molecular alcohols, aliphatic halogenated hydrocarbons or aromatic hydrocarbons. The formation of these condensation products, which contain, for example, polyvalent metal monohydroxy alcoholates and phosphoric acid monoalkyl in diiferent molecular proportions;- is accomplished by combining solutions of the starting components in the above solvents and thereafter heating the resulting mixture for a short time, if'necessary, to temperatures between 30 and 50 C. The starting componentsare used in a molar ratio of alcoholate to phosphoric acid ester from 1E0.5 to 1:1.5, but other molar ratios may also be used. In place of the finished condensation products, solutions of the starting materials in the solvents may also be used for direct application to the fibrous material. Furthermore, after completion of the condensation reaction, the solvents may also be distilled off and the residue may be dissolved in other suitable media which are customarily used toproduce impregnations on fibrous'materials, such as vegetable, animal or mineral oils, fats or waxes.

If necessary, small amounts of a complex-stabilizing compound may be added to the solutions[ Products of this type, which'are often characterized by the presence of readily exchangeable hydrogen atoms, are, for example,

hydrocarboxylic 'acid esters, 'compounds with reactive methylene groups, hydroxy-oxo compounds which are capable of being arranged into anacidic form, such as acetylacetone and acetoacetic acid ester, as well as oximes and {so forth. By the inclusion of such additivesintothe above-described solutions, the-premature decomposition of the solutions orthe condensation products through the.

action of moisture is prevented; the decomposition of the solutions or the condensation products by moisture may result in undesirable precipitates on the surface of the finished fibrous materials. 7

The present invention is particularly well adapted for the production of water-repellent impregnations on textile materials in the form of fibers, flakes, threads, ribbons, woven fabrics, knitted fabrics made of natural or synthetic fiber materials, especially rayon, spun rayon,

cotton, linen, hemp, jute, silk, wool, as well as fully synthetic fibers, such as polyamide and polyester fibers, V polyacrylicester and polyacrylic-nitrile fibers, polyvinylchloride fibers, alignate fibers,'glass fibers, and the like.

Similarly, other fibrous-materials, suchas, paper,*cardboard, cellulose, wood pulp, wood, and the like, may be rendered water-repellent with the aid of the waterproofing agents described herein.

The application of the waterproofing agents in accordance with the present invention is, however, not strictly limited to fibrous materials. Non-fibrous materials may also be rendered water-repellent therewith. Non-fibrous materials to which the waterproofing agents may advantageously be applied include the surfaces of plastics, painted surfaces, metal surfaces, and so forth. Furthermore, ceramic materials and other porous building materials may also be rendered waterproof by impregnation with the condensation products or solutions described above.

The process according to the present invention may advantageously be practiced by immersing the materials to be waterproofed in solutions which contain about 0.5 to 5.0%, preferably from 2 to 3%, by weight of-the above-described condensation product or mixtures thereof, or by brushing, and especially by spraying, such materials with these solutions. Depending upon the concentration used and the operating conditions, various hydrophobic effects may be obtained, such as water-repellent effects, water-resistance or water-impermeability.

The fibrous materials are preferably subjected to the impregnation in the dry state. After the impregnation with the waterproofing agents, the fibrous material is advantageously heated for a short period of time, if necessary in the presence of moisture, for example with the aid of steam, whereby the waterproofing effects are still further improved.

The waterproofing agents used in the examples below were produced by first dissolving the metal alcoholates in an organic solvent, such as in trichloroethylene or benzene, and thereafter stirring a solution of the high molecular acid phosphoric acid alkyl ester in an identical or similar solvent into the metal alcoholate solution. After the two solutions were combined, the solution mixture was heated for a short period of time, for example from 3 to 6 minutes. The solution mixture was then ready for use in the impregnation step. It may, however, also be admixed with small amounts of a stabilizing agent. The solution mixture was used in the resulting concentration or in a more diluted state, which was achieved by merely adding more of the respective solvent.

The following examples will further illustrate the present invention and enable others skilled in the art to understand our invention more completely. It is understood, however, that the invention is not limited to the materials and conditions recited in these examples.

Example 1 A ribbon of acetate rayon was immersed into a gasoline solution which contained 50 gm./liter of liquid wax having a melting point of 45 C., 2 gm./liter acetylacetone and 50 gm./liter of a condensation product formed by aluminum isopropylate and acid monophosphoric acid ester mixture of technical-grade fatty alcohols having from 12 to 18 carbon atoms in the molecule. The condensation product was a mixture of compounds having the structural formulas CnHaau O wherein n is an integer from 12 to 18, inclusive. Thereafter, the acetate rayon ribbon was centrifuged until the 4 increase in weight was about 25%, and then dried at 100 C. The dry ribbon exhibited an excellent waterrepellent effect, a soft, pleasant feel and also good antistatic properties.

Example ll Raincoats made of cotton poplin were immersed for 5 minutes into a stationary carbon tetrachloride solution which contained 10 gm./ liter soft parafiin having a melting point of 38 to 40 C., 10 gm./liter of a condensation product formed from 1 mol aluminum isopropylate and 0.7 mol of an acid monoalkylphosphate mixture, the alkyl radicals of which contained from 16 to 18 carbon atoms, and-l gm./liter acetylacetone. The condensation product was a mixture of compounds having the structural formulas and P\ /AI.OC:H1 nHInHO 0 wherein n is an integer from 16 to 18, inclusive. The intpregnated raincoats were centrifuged until the weight increase was about and thereafter dried at 60 to 80 C. The impregnated, dry coats had a pleasant feel and exhibited good water-repellent properties after ironing or steam-pressing.

Example III After impregnation, the nettle fabric was centrifuged and dried in the usual manner. The dry fabric exhibited good water-repellent properties.

Example IV Perlon fabric was immersed into a carbon tetrachloride solution which contained 20 gm./liter of a condensation product produced from 1 mol aluminum isopropylate and 2.5 mols of an acid monoalkylphosphate mixture, the alkyl radicals of which contained from 8 to 18 carbon atoms. The condensation product was a mixture of compounds having the structural formulas shown in Examples I and vIIabove, except that n was an integer from 8 to 18, inclusive; After impregnation of the Perlon fabric, it was centrifuged until its weight increase was about 50%, and thereafter dried at 80 C. The dry, impregnated fabric had a soft feel, exhibited good water-repellent properties and, in addition, antistatic properties. r

Example V Wooden objects were brushed with a trichloroethylene solution which contained 20 gm./liter of hard parafiin and 20 gm./liter of the condensation product described in Example I above formed from aluminum isopropylate and an acid phosphoric acid monoalkyl ester mixture. The wooden objects were then air-dried, whereupon they exhibited excellent water-repellent properties. The waterproofing impregnation may also be combined with other customary wood impregnations, for example with impregnations against rotting and the like.

Example VI Paper or cardboard webs were impregnated with a gasoline solution containing 5 gm./liter of the condensation product described in Example I above, either by spraying or by immersion. Thereafter the fibrous material was dried in the customary fashion, whereupon it exhibited excellent water-repellent properties.

Example VII structural formulas cm aro and O CsH'l OCaH1 The impregnated felt materials were squeeze-dried and then fully dried by heating. The dry, impregnated felt material exhibited excellent Water-repellent properties.

Example VIII Woolen overcoat cloth was immersed into a trichloroethylene solution which contained gm./liter of the condensation product formed by 1 mol titanium isopropylate and 1.3 mols of the acid monophosphoric acid ester mixture of technical-grade fatty alcohols having from 12 to 18 carbon atoms in the molecule, as well as 10' gm./

liter of hard paraffin having a melting point of 50 C.

The condensation product was a mixture of compounds having the structural formulas wherein n is an integer from 12 to 18, inclusive. After squeeze-drying and then air-drying the woolen fabric, it

exhibited excellent water-repellent properties and had a soft, pleasant feel. Substantially the identical effect was obtained when the condensation product formed from 1 mol zirconium isopropylate and 0.9 mol of an acid alkylphosphate mixture, wherein the alkyl radicals had from 12 to 18 carbon atoms, was used instead of the titanium condensation product.

While we have illustrated certain specific embodiments of our invention, it will be readily apparent to those skilled in the art that the present invention is not limited to these specific embodiments and that various changes and modifications maybe made without departing from the spirit of the invention or the scope of the appended claims.

We claim:

1. The process of waterproofing fibrous materials, which comprises impregnating said fibrous materials with a condensation product formed by a condensation reaction between (A) alcoholates of polyvalent metals selected from the group consisting of aluminum, magnesium, titanium and zirconium and (B) diacid phosphoric acid mono-esters of high molecular-weight organic hydroxyl compounds containing at least 6 carbon atoms, said alcoholates and said monoesters being present in a molar ratio of from 1:05 to 1:1.5, said condensation product being in solution in an inert organic solvent, and evaporating the solvent.

2. The process of waterproofing fibrous materials according to claim 1, wherein said polyvalent metal alcoholates are aluminum alcoholates.

3. The process of waterproofing fibrous materials, which comprises impregnating said fibrous materials with a condensation product formed by a condensation reac-v tion between (A) alcoholates of polyvalent metals selected from the group consisting of aluminum, magnesium, titanium and zirconium and (B) diacid phosphoric acid mono-esters of high molecular-weight organic hydroxyl compounds containing at least 6, carbon atoms, said alcoholates and said monoesters being present in a molar ratio of from 1:05 to 1215, said condensation product being in solution in an inert organic solvent, said solution also comprising an organic complex-stabilizing atoms, evaporating the solvent and drying compound, and evaporating the solvent.

4. Theprocess of waterproofing fibrous materials, which comprises impregnating said fibrous materialswith a solution mixture consisting of a solution of an (A) alcoholate of a polyvalent metal selected from the group consisting of aluminum, magnesium, titanium andzirconium in an inert organic solvent and (B) a solution of diacid phosphoric acid mono-esters of high molecularweight organic hydroxyl compounds containing at least 6 carbon atoms in an inert organic silvent, said alcoholate and said monoesters being present ina molar ratio of from 1:05 to 151.5, and drying the impregnated fibrou material at elevated temperatures.

which comprises impregnating said fibrous materials with a solution in an inert organic solvent of the'condensation product of 1 mol of an aluminum isopropylate and from 0.5 to 1.5 mols of a diacid mono-alkyl ester of phosphoric acid, said alkyl radical containing 12 to 18 carbon the impregnated fibrous material.

References Cited in the file of this patent UNITED STATES PATENTS 2,801,190 Orthner et a1. July 30,1957 

1. THE PROCESS OF WATERPROOFING FIBROUS MATERIALS, WHICH COMPRISES IMPREGNATING SAID FIBROUS MATERIALS WITH A CONDENSATION PRODUCT FORMED BY A CONDENSATION REACTION BETWEEN (A) ALCOHOLATES OF POLYVALENT METALS SELECTED FROM THE GROUP CONSISTING OF ALUMINUM, MAGNESIUM, TITANIUM AND ZIRCONIUM AND (B) DIACID PHOSPHORIC ACID MONO-ESTERS OF HIGH MOLECULAR-WEIGHT ORGANIC HYDROXYL COMPOUNDS CONTAINING AT LEAST 6 CARBON ATOMS, SAID ALCOHOLATES AND SAID MONOESTERS BEING PRESENT IN A MOLAR RATIO OF FROM 1:0.5 TO 1:1.5, SAID CONDENSATION PRODUCT BEING IN SOLUTION IN AN INERT ORGANIC SOLVENT, AND EVAPORATING THE SOLVENT. 